An ordinary flashlight uses two D-cell 1.5-V batteries connected in series as in Fig. 18-4b (Fig. 18-36).

Question:

An ordinary flashlight uses two D-cell 1.5-V batteries connected in series as in Fig. 18-4b (Fig. 18-36). The bulb draws 450mA when turned on.
(a) Calculate the resistance of the bulb and the power dissipated.
(b) By what factor would the power increase if four D-cells in series were used with the same bulb? (Neglect heating effects of the filament.) Why shouldn€™t you try this?

An ordinary flashlight uses two D-cell 1.5-V batteries connected